This new species, named after our former zoologist, is more than twice the size of R. australis, being two or more inches in length of body, with slender arms some six or more inches long, and a comparison of the respective indices for the external features serves to remove it from that species, whilst the genital apparatus are also distinctive. It differs also from R. fontiniana D'Orbigny.

External Features (figs. 1, 2).

The body of the male is oval, rounded posteriorly; that of the female, however, is globular. Such differences in form of body have already been recorded by Robson (Trans. Zool. Soc. 1927) for O. horridus and in his monograph (1929) for other species, and by myself for R. australist This difference may be due to the state of contraction of the body at the moment of death, for I noted in R. australis that it has no relation to the sex.

The colour is dark purplish grey, much darker in the female, which indeed is almost black, but somewhat paler in the male, which has been longer in formalin. In the male there is a difference in marking, in that the ground colour is relieved by numerous circular and closely set orange spots which appear to be low papillae flattened by poor preservation. These spots are continued along the back of the arms.

The surface appears smooth, unless these spots are really papillae, and scattered over the dorsum are about a dozen conical tubercles, some of which are produced into cylindrical threads of about 3 mm. in length. One pair of these on the mesial side of the eyes are flattened rather than thread-like and attain a length of 5 mm., with the extremity produced into few short processes. They no doubt represent the “supraocular” cirri. In the female such spots are absent; and the “sculpture” consists of closely set rounded pustules or papillae containing fluid, of uniform size, dark grey in colour like the ground.

The ventral surface of both is very pale and quite smooth. Dimensions (in millimetres).

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Thus the arms are subequal, but the dorsal is shortest. The hectocotylised arm is 105 mm. The ligula 8, and the calamus 3 mm. The hectocotylised has the form characteristic of the genus in its thick inturned lateral lips.

The web (or umbrella) has its various sectors subequal; it is short, not being continued far along the arms: reaching only to the 9th sucker, except of course in the hectocotylised arm.

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The measurements of arms and web are taken from the mouth along the inner surface of these organs.

The suckers gradually increase in diameter till the 11th or 13th, which are 4 mm. across; they then suddenly decrease in size.

The mantle aperture—the entrance to the pallial chamber—is wide (Robson's “C”) reaching almost to the eyes. The funnel is about the same length as the ventral sector of the web in the male, but in the female reaches only about halfway along the web. Perhaps this is due to differences of contraction.

Mantle Chamber.

When fully exposed the funnel is 25 mm. long, with an adsiphonal pouch on either side, whose height is 10 mm. and width 14 mm.

The funnel lock is weak, consisting of a right and left reflected edge of the funnel base separated by a median arched gap 5 mm. across.

I see no funnel organ.

The septal aperture, by which the right and left chambers communicate, is of about the same length as the region of the septum in front of it. That is, it is of the usual large size.

Reproductive Apparatus (figs. 4, 5).

In the female the ovipore is situated as in R. australis far back at the base of the gill, on a rather large but low rosette-shaped papilla (fig. 4 op.), in front of and just mediad of the tubular renal papilla. As in R. australis the spermoviducal gland presents what appears to be an unusual condition, though this may be due to my ignorance of the literature; it consists of two chambers, one thick walled (a) receiving the proximal oviduct (or “ovarian duct,” od) is indeed a pale dilatation of this duct which leads into and is partly embedded in a second chamber (b), which is thin walled, bladder-like of a dark, almost black, tint, due to its contents, from the hinder region of which arises the distal oviduct or “vagina,” a short, thick, muscular tube which curves alongside the chamber “b” to reach the ovipore (fig. 5). This bladder (b) is lined by columnar epithelium of cells of varied shape, and size containing refringent globules which in mass are opaque; hence the dark colour of the bladder.

I found no spermatozoa, which is not surprising as the animal had but recently laid her eggs.

The eggs were laid while the octopus was living in the tank at the aquarium at Portobello, and though I received them as

loose groups or clusters they were probably deposited in a lamellibranch shell as were those of R. australis.

This mass of eggs consisted of numerous clusters, each measuring from 30 to 70 mm. in length; each cluster is made up of very many eggs attached to a black axial thread by which the cluster was attached (?) to the shell. In a cluster or bunch of 30 mm. there were about 24 circles of eggs with 20 eggs in a circle; there were about 60 such bunches in the mass when received, so that at least 30,000 eggs had been laid.

The individual egg is ovoid, about 3 mm. long and half as much in width. Some had already commenced to develop, though others show no progress. In the former the eight arms are represented by short, nearly circular, masses of cells. I was unable to detect other structures.

The Male Organs (figs. 6, 7).

The penis possesses the second diverticulum characteristic of the genus, but instead of this being globular, as it is in R. australis, it is a long oval or sausage shaped, lying above, and so hiding, the primary diverticulum (fig. 6.d2).

The slender penial duct (“distal vas deferens” pd.) leads into a pyramidal chamber, which lies in front of and dorsal to the subspherical “packet” of convoluted tubes (pk.) that constitute the main part of the system, and lies in front of the testicular sac (T). This pyramidal chamber is the enlarged distal region of Needham's pouch (N). Into it the accessory gland and the spermatophoral gland open close together, a little in front of the middle (fig. 7, acc. and sp.gl.).

This enlargement of Needham's pouch as well as its tubular prolongation posteriorly contained spermatophores, which as usual have their “spermtube” directed forwards. The accessory gland is about twice as long as the tubular region of Needham's pouch, being 40 mm. long when extended. Its posterior extremity is sharply recurved and dilated, and at its anterior end where it opens into the pouch there is a small “appendix.” It will be seen that the apparatus is much less elaborate than in R. australis.

As to the alimentary tract it is sufficient to note that the ink sac (is) is embedded in the liver; that is, it is sunk below the membrane that encloses the liver (l), while its slender duct is free for its entire length (fig. 3). br.h., branchial heart; c., stomach; r., renal sac.

In dissecting out the female organs the heart was exposed. The ventricle (v) is spherical, and into it there opens on each side an “auricle,” or at any rate a thin-walled and much dilated branchial vein (au), giving all the appearance of an auricle such as occurs in Sepia, though in the few illustrations of octopods at my disposal, e.g., O. vulgaris and Eledone cirrosa such an “auricle” is not indicated, the vein not being noticeably enlarged at its entrance into the ventricle.